configs: remove CONFIG_CROSS_COMPILE_COMPAT_VDSO
    
    The Kconfig symbol CROSS_COMPILE_COMPAT_VDSO was dropped in v5.4-rc3,
    see upstream commit 50a2610adec9 ("lib: vdso: Remove
    CROSS_COMPILE_COMPAT_VDSO"). So drop it from the configuration
    generation system too.
    
    Signed-off-by: Paul Bolle <pebolle@tiscali.nl>